Electron Spectroscopy for Chemical Analysis (ESCA) represents perhaps the most valuable surface analysis tool available for the biomaterials scientist. The objective of this proposal is to develop a state-of-the-art ESCA facility for exploring new ESCA techniques as applied to biomaterials and which will be available for use by researchers for studying biomaterials and blood compatibility. Specific areas in which this facility would be used include: (A) Fundamental research by the core group on the use of ESCA for biomaterials studies and for predicting blood and tissue compatibility; specifically (1) variable angle ESCA studies for non-destructive depth profiling and surface heterogeneity assessment; (2) surface energy analysis using ESCA; (3) ESCA studies to establish the relationship between surface chemistry and blood interactions; (4) ESCA for investigating hydrated interfaces; (5) adsorbed protein configuration and organization as studied by ESCA and (6) propagation of surface effects through contaminant layers. (B) A repository of standard spectra, particularly for reference materials and other accepted biomaterials. (A data system would be developed for storing, accessing and comparing spectra.) (C) A quality control and routine analysis service for N.I.H. biomaterials contractors and grantees. (D) A teaching center for predoctoral and postdoctoral education in ESCA and other surface analysis methods with particular emphasis on biomedical materials. (E) A collaborative research center offering researchers a facility for the development of new ideas and surface analysis techniques. (F) Organization of a symposium to disseminate new knowledge concerning ESCA and its use for the analysis of biomaterials and blood surface interactions. In the second and third years of operation of this center Scanning Auger Microprobe and Secondary Ion Mass Spectrometry capabilities will be added to make the center more generally useful for biomedical surface analysis problems.